Two longitudinal studies examine the relationship of maternal PTSD and depression to the mental health and behavior of children who were affected by the 9/11 terrorist attacks. The first study found that preschoolers of mothers who experienced PTSD and depression symptoms exhibited more clinically significant behavior problems. The second study found that direct exposure to 9/11 played a small but significant role in explaining the prevalence of the mothers' and adolescents' PTSD and depression rates.